Internal-combustion engine.



No. 856,790. PATENTED JUNE 11, 1907. E. H. MIGKLEWOOD & H. WHIDBOURNE. INTERNAL COMBUSTION ENGINE.

APPLICATION FILED APR.8.1907.

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'INTERNAL COMBUSTION ENGINE.

APPLICATION FILED APR.8,1907.

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UNITED STATES PATENT orrron.

EDMUND H. MICKLEWOOD AND HARRY WHIDBOURN E, OF PLYMOUTH, ENGLAND.

INTERNAL-IHCOMBUSTION ENGINE.

Specification of Letters Patent.

Patented June 11, 1907.

Application filed April 8, 1907- fl N 367,061.

A To a/ whom it may concern.-

. air charge fromthe other end of the chamber during t Be it known that we, EDMUND HAW- THORNE MicxLnwoon and IIARRY l/VH1D- BOURNE, both subjects of the King of Great Britain, residing respectively at 5 St. Michaels Terrace, Plymouth, in the county of Devon, England, engineer, and 51 Greenbank avenue, Plymouth, in the county of Devon, England, watchmaker, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification:

This invention relates to internal combustion engines and to a construction thereof in which an annular extension of the engine piston working in an annular cylinder or chamber formed between an outer wall coaxial with the working cylinder and a fixed sleeve over which the piston trunk slides. According to the present invention this annular chamber is utilized on alternate strokes of the engine for compressing the whole or part of the working charge into the engine cylinder and for compressing a charge for scavenging the engine cylinder, whereby a two stroke cycle engine is obtained, suitable valve controlled passages and ports being provided for this purpose. The opposite ends of the annular chamber or pump cylinder are connected by conduits with the working cylinder so that a compressed charge of air or of combustible gas or vapor or ofa mixture of combustible gas or vapor and air is delivered to the working cylinder from one end of the annular chamber during one stroke of the piston, and a scavenging e return stroke of the iston. The conduits are controlled by va ves in such manner that the charge of air or combustible, as the case may be, is first trapped in the annular chamberand then, after compression, allowed to pass into the working cylinder;

In the accompanying drawings,-which are more or less diagrammatic, Figure 1 is a central longitudinal section of a vertical type of engine embodying the present invention;

Fig." 2 is a central section through an accessory which may be used with the engine;

- Fig. 3 is a part section of the engine cylinder showing a device for regulating the pressure of the working charge; Fig. 4 is a view s milar to Fig. 1, but showing a slightly modified then arrangement of conduits and valves; and Fig. 5 is a section on line 55 of Fig. 4.

Referring first to Fig. 1, the piston A operates in the working cylinder B in the usual manner and has a hollow or open ended extension A which works in an annular chamber B formed in a pump cylinder co-axial with the working cylinder B. The pump cylinder is formed by the lower portion of the cylinder body or casting, which for this purpose is made of greater internal diameter than the working cylinder, and the chamber B is formed by said lower portion of the cylinder body or casting and a sleeve B which is secured Within the said lower portion of the cylinder body and fitted to the interior face of the hollow piston trunk.

The sleeve is fitted with rings B to prevent the escape of any fluid between it and the piston trunk, and the working piston A and pump piston A are also fitted with rings A A respectively in the usual manner.

A conduit C connects the rear end of the chamber B with the rear end of the cylinder, but its communication with the cylinder is controlled by a non-return valve 0. At a convenient point of the conduit C is an inlet passage D controlled by a non-return valve D. The valves C, D are adapted to admit fluid to the cylinder B and conduit C respectively. The forward end of the cham ber B is connected by a conduit E and port or orts E with the forward end of the wor 'ng cylinder in which also are ports B which communicate with the exhaust conduit, not shown in the drawings, and which are uncovered by the piston A before it reaches the end of the outward stroke. At a convenient point in the conduit E is an outlet assage F controlled by a non-return valve adapted to admit fluid tothe conduit E.

The operation of this engine is as follows: The piston A is shown in the drawings at the end of the working stroke when exhaust has taken place through the ports B uncovered by the piston. In this osition of the piston the port E is uncovered and a charge of air or neutral gas, which in the two receding strokes has first been drawn into t e chamber B in front of the piston A through the inlet passage F, valve F and conduit E, and

een compressed in the chamber B and conduit E, thereby admitted to the Working cylinder. The piston A may be provided with a baiiie A as shown, 0 posed to the entering fiuid so as to deflect the latter and prevent a straight blow through the exhaust orts B, so that a thorough scaven ing is efected and the working cylinder is Y lled with a charge of cool air at atmospheric pressure with only a small admixture of the residual roductsof combustion. During the working stroke a second charge of air or a combustible charge is drawn into the chamber B and conduit C in rear of the piston A through conduit D and valve D, and this charge is compressed in the chamber B and conduit C on the return or compression stroke of the piston simultaneously with the -compression of the charge in the working cylinder. The pressure in the chamber B and conduit 0 increases more ra idly however than the-pressure in the wor ing cylinder, firstly because compression does not begin in the working cylinder until the exhaust ports- B are covered by the piston A, and secondly because the stroke volume of the piston A is arranged to be a greater fraction of the total volume of the chamber B and conduit C than the stroke volume of the working piston A is of the total volume of the cylinderB. Consequently the charge in chamber B and conduit C will begin to enter the working cylinder practically at the beginning of the com ression stroke and will continue to enter unti the end of the stroke unless means are provided to relievethe pressure in the chamber B at any intermediate point of the stroke. During the compression stroke also, the piston A draws a fresh charge of fluid through conduit F and valve F into the chamber- B on the front side of the iston A, this charge being trapped by the c osing of the valve F and compressed during the working stroke of the piston until the port E, which remains covered until after the exhaust ports B are uncovered, is uncovered by the piston A, and the charge compressed in the conduit E and forward end of the chamber B is then allowed to enter the working cylinder as already described, whereupon the cycle of o erations is repeated. If a combustibi charge is admitted by the valve D no other device is required for the admission of fuel to the working cylinder, but when air only is admitted by this valve suitable means must be provided for injecting the fuel. A suitable pump for this purpose is shown in Fig. 2. The ump body G has a screw threaded nipple i for insertion in the screw threaded hole Gr in the cylinder wall which is shown closed by a plug G in Fig. 1. A spring controlled plunger Gr slides in a longitudinal bore of the casting which communicates on the one hand with a duct G for admission of fuel to the pump, and on the other hand with a duct Gr extending through the nipple G through which the fuel is injected by the any suitable mechanism and may be arpump plunger into the working cylinder. The duct G is controlled by a conical valve G held on its seat by a spring G while the duct Gr requires no other valve than is provided by the plunger itself whichcrosses the point at which the duct enters the bore of the pump and as will be seen constitutes a measuring device insuring a constant volume of chargef The plunger Gr may be operated by ranged to be moved positively in both direc tions by the actuating mechanism instead of the return stroke being effected by a spring as shown. When it is desired to vary the compression of the working charge there may be provided, in addition to or in lieu of any suit able known means for throttling the charge, a series of ports H formed in a convenient part of the cylinder wall, the innerends of which ports are uncovered in succession during the latter part of the compression stroke and put into communication with the chamber B by means of a longitudinal groove-A on the outer face of the piston trunk. The

ports H 0 en into a valve chamber H and are contro led by a slide valve H by which one or more of the series of ports may be closed. If air only is forced into the working cylinder on the compression stroke the chamher H is open to the atmosphere, but if a combustible charge is used the chamber H is connected by a conduit H with the conduit D or with the source whence the charge is drawn in through the valve D. It will be seen that with this arrangement the com ression will vary according to the position 0 the valve H as if all the ports H are left uncovered by the valve H the chamber B will begin to return its charge to the conduit D, or discharge into the atmosphere, as soon as the recess A in the piston trunk reaches the first port H on the com ression stroke, whereupon the pressure in t 1e chamber B being thus relieved. the non-return valve C will close and no further charge will enter the working cylinder. If one or more of theports H are closed by the valve H the closing of the valve C will be delayed accordingly and the charge which enters the working 0 linder correspondingly increased. The position of the valve may be varied automatically by means actuated by a centrifugal overnor or otherwise controlled by the spec of the engine. It is advisable to relieve the pressure 1n the conduit C at the end of the compression stroke and for this ur 0% a single port such as indicated at ig. 1) may be provided coolplerating w1th a recess K in the piston, but

t 's relief device need not of course be provided when a device of the kind illustrated in Fig. 3 is used. The conduit E may be provided if desired with an enlargement constituting a storage chamber for the charge compressed in the chamber B on the outer side of the piston A, as the port E is prefer- 1 0 and B may alternatively be provi ed with valves, preferably positively actuated In the modified construction of Figs. 4 and 5, the duct is considerably shortened by interposing the valve C at an intermediate point of its length, the remainder of the duct, which is identified in Fig. 4 by the reference character B being permanently in free com-' munication with the rear end of the cylinder grid forming art of the combustion chamer.

The va ve arrangements controlling scavenging charge .are' reversed as com ared with the-construction of Fig. 1, the c arge being admitted to the chamber B through a suitable duct or ducts, such as the air trunks I formed within the body of the fixed sleeve B and orts I connecting the ducts with the cham er B, these ports beingcovered by the pistonitrunk until near the end of the re-' turn stroke of the piston when the air rushes in to fillthe, chamber B and the pipe J which connects the chamber with the cylin der B at any suitable oint through a nonreturn or other suitab e valve J. On the outward orworking stroke of the iston this charge is compressed withinthe c amber B and pipe J as soon as the piston trunk closes the ports I, and toward the end'of the working stroke the com ressed charge is admitted to the cylinder B t ough the opening of the valve J when the pressure in the cylinder falls below that of the scavenging charge, which then rushes into the cylinder and flushes the combustion products through the exhaust ports B; i

It should benoted that with the en ine constructed as herein described and il ustrated, the splash s stem of lubrication commonly used 1n engines of this ty e is in no waymterfered with, as the crap casing is not employed as a storage or" compression chamber. The piston A may be provided with lateral oil holes A as shown for the passage of the lubricant to the rubbing surfaces.

Having thus described the nature of this invention and the best means we know of cprrying the same into practical efiect, we 0 a1m:

g 1. In internal combustion engines, a work: 5 5

ing cylinder, a pump cylinder co-axial therewith, a fixed sleeve within said latter cylinder forming in connection with the cylinder an annular chamber, a trunk piston sliding over the said sleeve and having an annular extension constituting a pump piston work ing in said chamber, ducts connecting the chamber at the front and-rear of the pump piston with the working cylinderand a-source of fluid supply, and valves controlling said ducts. y

2. In internal combustion engines, a working cylinder, a pump cylinder co-axial therewith, a fixed sleeve within said latter cylinder forming in connection with the cylinder an annular chamber, a trunk piston sliding over the said sleeve and having an annular extension constituting a pump piston working in" said chamber, ducts connecting the chamber at the front and rear of the pump piston with the working cylinder and a source of fluid supply, valves controlling said ducts, a plurality of orts adapted to communicate with said 0 amber, a channel in the trunk piston adapted to establish such communication, and means for closing the outer ends of any desired number of said ports. I

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

E. H. MIoKLEWoon, H. WHIDBOURNE. 

